what is positive ion?

An ion is a particle which has either a positive charge or a negative charge. Ions can also be defined as atoms or molecules with a charge. In them, the total number of electrons is not equal to total number of protons.

If, the number of electrons is less than the number of protons, then it has a positive charge and is called cation or positive ion.

 Example: Mg²⁺ , Na⁺